Weaving Machine Comprising Pneumatic Weft Insertion

ABSTRACT

The weaving machine comprises a pneumatic weft insertion. It is fitted with a weaving reed ( 12 ), wherein a guiding device ( 42 ) is associated with a guiding channel ( 40 ) for a weft thread ( 10 ). The guiding channel ( 10 ) comprising the weaving reed ( 12 ) can be pivoted between an insertion position and a stop position for the weft thread ( 10 ). Also, a fixed weft thread insertion device ( 8 ), which comprises at least two blast nozzles ( 22 ), is associated with the guiding channel ( 40 ) in the insertion position. A fixed blade ( 46 ) is used to cut the inserted weft thread ( 10 ). The blast nozzles ( 22 ) are pivotably mounted in the transversal direction (Q) counter to the blade ( 46 ) in order to improve the weaving machine and are connected by means of a motor drive device ( 28 ) in order to displace the blast nozzles ( 22 ) counter to the blade ( 46 ).

This application claims priority of PCT application PCT/CH2006/000340 having a priority date of Oct. 5, 2005, the disclosure of which is incorporated herein by reference.

TECHNICAL FIELD

The invention relates to a weaving machine comprising pneumatic weft insertion.

BACKGROUND OF THE INVENTION

A weaving machine comprising pneumatic weft insertion of the type initially mentioned is known, for example, from WO 97/13901. The weaving machine has a reed which is assigned a guide device with a guide duct for a weft thread. The guide duct is pivotable, together with the reed, between an insertion position and a beating-up position of the weft thread. Furthermore, the guide duct is assigned, in the insertion position, a fixed weft insertion device with blow nozzles, which is therefore independent of the reed and therefore, on the one hand, does not impair the movement of the reed and, on the other hand, is also not impaired itself by the movements of the reed. Shears serve for cutting off the inserted weft thread. The blow nozzles are arranged pivotably in the vertical direction and are driven by a Jacquard device and a return spring. By means of the Jacquard device, in each case two blow nozzles are presented in pairs to the guide duct, in each case only one blow nozzle being used. Since the shears cut off the inserted weft thread at the insertion point of the blow nozzle, the inserted weft thread has to be held by means of a clamping device as far as the beating-up edge. The clamping device is assigned to the reed and is moved together with the latter. The clamping device, however, is relatively complicated and susceptible to faults. Moreover, the height control of the blow nozzles by means of the Jacquard device is likewise relatively complicated and has only a restricted flexibility and accuracy.

WO 00/63464 A1 discloses a weaving machine comprising pneumatic weft insertion, in which a plurality of blow nozzles of a weft insertion device are arranged pivotably in the vertical direction by means of a drive device, in order to align said weft insertion device selectively with the guide duct. The disadvantage of this is that the weft insertion device on the batten and the drive for the nozzles are arranged fixedly. This not only leads to a complicated drive, but also to increased mass forces due to the to-and-fro movement of the batten together with the weft insertion device. These mass forces are detrimental to the beating-up frequency. The acceleration and deceleration forces associated with the movement also have an adverse effect on the stability of the weft insertion device. To cut off the inserted weft thread, the entire weft insertion device, together with the batten, is moved up against a cutting device. There is no pivotability of the blow nozzles transversely to the vertical direction.

DE 30 14 776 A1 discloses a further weaving machine comprising pneumatic weft insertion, in which a plurality of blow nozzles of a weft insertion device are arranged pivotably in the vertical direction and in the transverse direction, in order to align a selectable blow nozzle with a guide duct on the batten. The weft insertion device is arranged on the batten, thus resulting in the disadvantages already referred to above. As regards the actual drive of the blow nozzles, no actual particulars are given, not even any interaction with any cutting device.

SUMMARY OF THE INVENTION

The object of the invention is to improve a weaving machine comprising pneumatic weft insertion of the type initially mentioned. In this case, on the one hand, a clamping solution, as in WO 97/13901, is to be capable of being dispensed with and, on the other hand, the disadvantages of the overloading of the movable batten, which arise from WO 00/63464 A1, are not to be taken into account.

Since the blow nozzles are mounted pivotably in the transverse direction toward the shears and are connected to a specific motor drive device, in order to move the selected blow nozzle toward the shears exactly, the inserted weft thread is cut virtually only when it enters the shears. It is thereby possible to shift the cutting off of the inserted weft thread into the beating-up region of the weft thread, so that there is no longer any need for a clamping device. This not only simplifies the weaving machine, but also increases the accuracy of insertion of the weft thread.

A refinement is particularly advantageous, according to which the drive device is designed such that the cutting of an inserted weft thread takes place in the region of the beating-up edge of the cloth web. In this case, the weft thread has already assumed a reliable position, so that, even after cutting off, a displacement of the weft thread is no longer possible.

The accuracy and operating reliability of the weaving machine can be improved if the drive device is designed such that the blow nozzle used in each case is oriented in the transverse direction at least approximately coaxially to the guide duct.

Particularly when blow nozzles arranged one above the other in the vertical direction are used, the design according to which the blow nozzles are mounted pivotably and can be driven further in the vertical direction transversely to the transverse direction. This drive may take place in a known way by means of the Jacquard device. However, the design is more advantageous, according to which the blow nozzles are connected to a further separate motor drive device for the vertical direction, in order to align one of the blow nozzles at least approximately with the guide duct in the vertical direction. This refinement is advantageous particularly when the weft insertion device has a plurality of blow nozzles arranged in the transverse direction and in the vertical direction.

For example, a servomotor, a direct-current motor or, in particular, an AC motor is suitable for the motor drive device.

The weaving machine has a control device for pattern control, which, moreover, is connected to each motor drive device for the control of the latter, so that weft threads of different color or quality can be used as a function of the patterned fabric to be produced.

The weaving machine is preferably configured such that, in the event of a thread break, the control device prevents the weft thread from being movable into the shears, so as to discharge the broken weft thread and draw up a new portion of the weft thread.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the weaving machine are described in more detail below with reference to diagrammatic drawings in which:

FIG. 1 shows the weaving region of a weaving machine in a view of the weft insertion device, during the insertion of a weft thread;

FIG. 2 shows the weaving machine of FIG. 1 in a view transverse to the vertical direction;

FIG. 3 shows the weaving machine of FIG. 1 during the beating up of a weft thread and during the cutting off of the weft thread;

FIG. 4 shows the weaving machine of FIG. 3 in a view from above.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1 to 4 show the weft insertion region of a weaving machine in a diagrammatic illustration, only the parts important for the present invention being shown. All the other features of the weaving machine are state of the art.

FIGS. 1 and 3 show the weaving region of a weaving machine, at which warp threads 2 are moved by means of a shedding device 4, for example a Jacquard device, to an open shed 6, into which a weft thread 10 is inserted by means of a weft insertion device 8. By means of a reed 12, the weft thread 10 is beaten up at a beating-up edge 14, so that a cloth web 16 is obtained.

The weft insertion device 8 is designed pneumatically and has a nozzle block 20 which, in the present example, has eight blow nozzles 22 which, according to FIG. 4, are arranged in pairs in transverse direction Q, according to FIG. 2 four pairs of such blow nozzles being arranged one above the other in the vertical direction H. The nozzle block 22 is arranged pivotably via a vertical axis 24 in the transverse direction Q and is mounted pivotably about a horizontal axis 26 in the vertical direction H. A first drive device 28 contains a motor 30 which is connected to the blow nozzles 22 via a lever mechanism 32. A second drive device 34 for pivoting the blow nozzles 22 in the vertical direction H is arranged in a similar way. This second drive device has, again, a motor 36 which is connected to the blow nozzles 22 via a further lever mechanism 38. The first drive device 28 and the second drive device 34 serve initially for selecting one of the blow nozzles 22 and for aligning it coaxially with a guide duct 40 of a guide device 42 which is connected to the reed 12 and serves for guiding an inserted weft thread 10. Staggered nozzles 44 serve for the forward movement of the inserted weft thread along the guide duct 40.

Moreover, the first drive device 28 serves for moving the blow nozzles 22 toward fixed shears 46 which are arranged in the region of the beating-up edge 14 of the cloth web 16 in such a way that the shears 46 take effect virtually only when the inserted weft thread 10 is virtually beaten up at the beating-up edge 14, as may be gathered from FIGS. 3 and 4.

A control device 50 connected to the first and to the second drive device 28, 34 serves for the pattern control of the weaving machine and consequently also of the first drive device 28 and the second drive device 34, in order in each case to select the blow nozzle 22 which is required for the pattern to be produced and by means of which the weft thread 10 required for the pattern is presented. Moreover, the control device also serves for controlling the drive devices 28, 34 such that the inserted weft thread is presented exactly to the shears 46.

LIST OF REFERENCE SYMBOLS

H Vertical direction

Q Transverse direction

2 Warp thread

4 Shedding device

6 Shed

8 Weft insertion device

10 Weft thread

12 Reed

14 Beating-up edge

16 Cloth web

20 Nozzle block

22 Blow nozzles

24 Vertical axis

26 Horizontal axis

28 First drive device

30 Motor

32 Lever mechanism

34 Second drive device

36 Motor

38 Lever mechanism

40 Guide duct

42 Guide device

44 Staggered nozzle

46 Shears

50 Control device 

1. A weaving machine comprising pneumatic weft insertion, with a reed which is assigned a guide device with a guide duct for a weft thread, the guide duct being pivotable, together with the reed, between an insertion position and a beating-up position for the weft thread, furthermore the guide duct being assigned, in the insertion position, a fixed weft insertion device with at least two blow nozzles, and also with fixedly arranged shears for cutting off the inserted weft thread, characterized in that the blow nozzles are mounted pivotably in the transverse direction toward the shears and are connected to a motor drive device, in order to move the blow nozzles toward the shears.
 2. The weaving machine as claimed in claim 1, characterized in that the drive device is designed such that the cutting of an inserted weft thread takes place in the region of the beating-up edge of the cloth web.
 3. The weaving machine as claimed in claim 1, characterized in that the drive device is designed for the at least approximately coaxial alignment in each case of a blow nozzle in the transverse direction with respect to the guide duct.
 4. The weaving machine as claimed in claim 1, characterized in that the blow nozzles are mounted pivotably and can be driven further in the vertical direction transversely to the transverse direction.
 5. The weaving machine as claimed in claim 4, characterized in that the blow nozzles are connected to a further motor drive device for the vertical direction, in order to align one of the blow nozzles with the guide duct in the vertical direction.
 6. The weaving machine as claimed in claim 1, characterized in that the weft insertion device has a plurality of blow nozzles arranged in the transverse direction and in the vertical direction.
 7. The weaving machine as claimed in claim 1, characterized in that the motor drive devices have in each case a servomotor, direct-current motor or AC motor.
 8. The weaving machine as claimed in claim 1, characterized in that it has a control device for pattern control, which is connected to each motor drive device for the control of the latter.
 9. The weaving machine as claimed in claim 1, characterized in that the control device is designed such that, in the event of a thread break, the weft thread is not movable into the shears.
 10. The weaving machine as claimed in claim 2, characterized in that the drive device is designed for the at least approximately coaxial alignment in each case of a blow nozzle in the transverse direction with respect to the guide duct.
 11. The weaving machine as claimed in claim 2, characterized in that the blow nozzles are mounted pivotably and can be driven further in the vertical direction transversely to the transverse direction.
 12. The weaving machine as claimed in claim 3, characterized in that the blow nozzles are mounted pivotably and can be driven further in the vertical direction transversely to the transverse direction.
 13. The weaving machine as claimed in claim 11, characterized in that the blow nozzles are connected to a further motor drive device for the vertical direction, in order to align one of the blow nozzles with the guide duct in the vertical direction.
 14. The weaving machine as claimed in claim 12, characterized in that the blow nozzles are connected to a further motor drive device for the vertical direction, in order to align one of the blow nozzles with the guide duct in the vertical direction.
 15. The weaving machine as claimed in claim 2, characterized in that the weft insertion device has a plurality of blow nozzles arranged in the transverse direction and in the vertical direction.
 16. The weaving machine as claimed in claim 3, characterized in that the weft insertion device has a plurality of blow nozzles arranged in the transverse direction and in the vertical direction.
 17. The weaving machine as claimed in claim 4, characterized in that the weft insertion device has a plurality of blow nozzles arranged in the transverse direction and in the vertical direction.
 18. The weaving machine as claimed in claim 5, characterized in that the weft insertion device has a plurality of blow nozzles arranged in the transverse direction and in the vertical direction.
 19. The weaving machine as claimed in claim 18, characterized in that the motor drive devices have in each case a servomotor, direct-current motor or AC motor.
 20. The weaving machine as claimed in claim 19, characterized in that it has a control device for pattern control, which is connected to each motor drive device for the control of the latter. 